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Manage My Life

Is Insulbrick a good vapor barrier?

I am trying to cover the exterior of my home with vinyl siding. The issue is the insulbrick siding I have on the walls now?Do I remove this siding before I install vinyl or can I cover it? What I want to do is cover the insulbrick with a 3/8 or 1/2 inch insulating board and then attach the vinyl siding.Some builders here in Winnipeg Manitoba say it is okay and others are saying I haveto remove the insulbrick because it does not breathe and will rot the walls.Some history on the house; it is around 100 years old and we replaced all the windows above ground, re insulated the walls from the interior and applied a vapor barrier in the walls and ceiling. I am hoping you can supply me with the correct (proper) way to install the vinyl siding.

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Manage My Life
On its best day, when it was brand-new, you might argue that insulbrick acted as a vapor barrier. Even then, there were experts to that would say that the number of joints in the insulbrick made it a bad vapor barrier. All these years later, I would not be concerned about the insulbrick breathing. It will likely breathe as well or better than the 3/8 inch or 1/2 inch insulating board that you intend to install.

Because your walls have been re-insulated, we would even questioned the necessity or the economic payback for the insulating board, unless of course the vinyl siding installers are looking for a smooth surface to start with. Any additional depth can make for odd looking reveals at protrusions through the wall, such as doors, windows, electrical masts and so on.
by Manage My Life
April 26th, 2007
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